Vibrator construction for the surface treatment of articles

ABSTRACT

A VIBRATOR CONSTRUCTION OF THE TYPE WHEREIN ARTICLES AND FINISHING MEDIA ARE DISPOSED IN A CONTAINER WHICH IS ASSOCIATED WITH A MOVABLE SUPPORTING STRUCTURE WHICH IS RESILIENTLY MOUNTED ON A BASE STRUCTURE. ECCENTRIC SHAFTS ARE MOUNTED INSIDE HOUSINGS WHICH ARE ATTACHED TO THE SUPPORTING STRUCTURE SO THAT DRIVING OF THE SHAFTS WILL IMPART VIBRATIONS TO THE CONTAINER FOR THE ARTICLES AND MEDIA WHEREBY INTIMATE CONTACT CAN BE ACHIEVED. THE ECCENTRIC   SHAFTS ARE LATERALLY OFFSET WITH RESPECT TO THE AXIS OF THE CONTAINER WITH ONE SHAFT HOUSING BEING SECURED TO THE SUPPORTING STRUCTURE ON EACH SIDE OF THE CONTAINER, AND WITH THE AXIS OF THE SHAFTS BEING IN ABOUT THE SAME PLANE AS THE CENTER OF GRAVITY OF THE CONTAINER HOLDING THE ARTICLES AND MEDIA. A COMMON DRIVE MOTOR IS PROVIDED FOR DRIVING BOTH ECCENTRIC SHAFTS.

1971 G. VAN FOSSEN 3,552,068

VIBRATOR CONSTRUCTION FOR THE SURFACE TREATMENT ARTICLES File d Sept. 9. 1968 4 Sheets-Sheet l INVENTOR Q 9 Zlzuewssezz/ M1? days Jan. 5, 1971 H. G. VAN FOSSEN- 3,552,068

VIBRATOR CONSTRUCTION FOR THE SURFACE TREATMENT ARTICLES Filed Sept. 9. 1968 I Q 4 Sheets-Sheet 2 6 6 I Il H MU fait 3% 46 22,

1 24 in .a

Jan. 5, 1971 v G VAN FOSSEN 3,552,068

VIBRATOR CONSTRUCTION FOR THE SURFACE TREATMENT ARTICLES Filed Sept. 9, 1968 4 Sheets-Sheet 5 FIG. 4

H. G. VAN FOSSEN VIBRATOR CONSTRUCTION FOR THE SURFACE TREATMENT ARTICL Jan. 5, 1971 4 Sheets-Sheet 4 Filed Sept. 9. 1968 FIG, 5

FIG. 7

FIG. 8

3,552,068 VIBRATOR CONSTRUCTION FOR THE SURFACE TREATMENT OF ARTICLES Harvey G. Van Fossen, Mishawaka, Ind., assignor to The Wheelabrator Corporation, Mishawaka, Ind., a corporation of Delaware Filed Sept. 9, 1968, Ser. No. 758,382 Int. Cl. B241) 31/06; 1302c 17/08 US. Cl. 51-163 Claims ABSTRACT OF THE DISCLOSURE A vibrator construction of the type wherein articles and finishing media are disposed in a container which is associated with a movable supporting structure which is resiliently mounted on a base structure. Eccentric shafts are mounted inside housings which are attached to the supporting structure so that driving of the shafts will impart vibrations to the container for the articles and media whereby intimate contact can be achieved. The eccentric shafts are laterally offset with respect to the axis of the container with one shaft housing being secured to the supporting structure on each side of the container, and with the axis of the shafts being in about the same plane as the center of gravity of the container holding the articles and media. A common drive motor is provided for driving both eccentric shafts.

This invention relates to vibrator constructions employed for the surface treatment of articles, for example, polishing or bumishing metal articles using steel balls as the media and soap-like liquids as a compound for lubrication. The surface treatment often also involves the cleaning, abrading, deburring or radiusing of surfaces of articles by means of abrasive finishing media and compounds which are located in the construction in intimate contact with the articles during the vibrating cycle.

Vibrator constructions have been employed for many years as means for treating the surfaces of articles. The constructions may be in the form of a bowl which will hold a batch of articles and finishing media whereby the vibration cycle can be carried out for a predetermined period of time after which the articles and media are removed. Continuous vibrators have also been utilized, and in such cases, articles and media are introduced at one end of an elongated trough, moved along the trough while being subjected to vibrations, and are finally discharged from the trough at the exit end. By continuously introducing the articles and media, an uninterrupted operation can be accomplished.

In the case of a conventional batch type operation, a single eccentric shaft is employed for imparting a type of elliptical vibrational movement to the bowl crosswise of its axis which vibrational movement is transmitted to the articles and media inside the bowl, causing them to rub against each other in the finishing operation. This elliptical vibrational movement also causes the mass of articles and media to slowly flow up one side of the bowl, across the top and down the other side of the bowl. During a finishing cycle, the mass of articles and media are vibrated for a time period during which they undergo a very large number of vibrations and the mass will roll or rotate about the bowl a relatively small number of times.

In the case of continuous vibrator equipment, an eccentric shaft is associated with the trough and the material in the trough is subjected to elliptical or orbital vibrations in the finishing operation. The material also slowly rolls about the trough. However, in this case the material in the trough is also displaced axially of the trough. Because of the axial displacement combined with the slow roll, in-

ted States Patent dividual portions of the articles and media move along the trough in a spiral path in a relatively uniform fashion, and pass out of a discharge opening.

It is a general object of this invention to provide improvements in vibrator constructions of the type previously utilized.

It is a more specific object of this invention to provide a vibrator construction which is capable of handling jobs which cannot be handled by conventional vibrators and which will accomplish the treatment of articles with substantially greater efficiency.

These and other objects of this invention will appear hereinafter, and for purposes of illustration, but not of limitation, specific embodiments of the invention are shown in the accompanying drawings in which:

FIG. 1 is a top plan view of a continuous vibrator characterized by the features of this invention;

FIG. 2 is a side elevational view of the construction;

FIG. 3 is an enlarged end view, partly in section, of the construction;

FIG. 4 is a schematic illustration showing the 'kind of vibrational motion and the relative magnitude of vibration at various points of the construction;

FIG. 5 is a schematic illustration showing the kind of vibrational motion and the relative magnitude of vibration at various points of conventional constructions;

FIG. 6 is an enlarged fragmentary, sectional view taken about the line 66 of FIG. 3;

FIGS. 7 through 9 are schematic illustrations of the top surface of articles and media as viewed from the side at various points along the length of different vibrator constructions; and

FIG. 10 is a schematic illustration showing the movement of articles and media at the top surface of the mass in one embodiment of the construction.

The vibrator construction of this invention generally comprises a container for receiving articles and media. The container is disposed on a movable supporting structure, and eccentric shafts are associated with the supporting structure for purposes of imparting vibrations to the container and to the material disposed therein.

The instant invention provides for the use of a pair of eccentric shafts which are offset laterally relative to the axis of the container. The shafts are supported :by the movable supporting structure, and are located on each side of the container. The vertical position of the shafts relative to the container axis is such that the axis of the shafts will generally correspond with the center of gravity of the articles and media located within the container.

The invention will be described with particular reference to a continuous vibrator construction; however, the features of the invention are equally applicable to batch type constructions. Thus, the same general type of supporting structures for the eccentric shafts can be utilized for also supporting a trough such as used with a continuous vibrator or a bowl as used in batch type constructions. However, in the continuous vibrator construction the eccentric shafts are at a slight angle of inclination to the longitudinal axis of the trough to provide a longitudinal component of vibration, whereas, in batch type constructions the eccentric shafts are parallel to the axis of the bowl.

FIGS. 1 through 3 illustrate a continuous vibrator construction 10 consisting of an elongated cylindrical container 12 having inlets 14 and 16 and a discharge chute 18. The inlet 14 is employed for the introduction of finishing media while the inlet 16 is utilized for introducing the articles to be finished.

The container 12 is mounted on a supporting structure consisting of four transversely extending plate assemblies 20. Each of these assemblies includes side portions 22 which support eccentric housings 24. In the embodimerit shown, a pair of the housings 24 is located on each side of the container 12. A shaft 26 extends into each front housing 24, and drive coupling 28 connects this shaft With a similar shaft extending into each of the rear housings. An eccentric 30 is located within each of the housings. This eccentric preferably comprises a rectangularly shaped bar connected off-center to the eccentric shafts. A removable plate 32 is secured to the eccentrics 30 so that adjustments may be made in the operation of the eccentrics. The housings 24 and the eccentric shafts 26 are at a slight fixed angle of inclination to the longitudinal axis of the container 12 to provide a longitudinal component of vibration which causes the media and parts to move from one end of the container to the opposite end. This angle of inclination is normally less than one degree.

Elongated bars 34 extend between adjacent side plates 22. A plurality of springs 36 extend between the bars 34, and upright supports 38. These upright supports are located on a base 40 which is in turn mounted on legs 42. The container is normally horizontal with the two eccentrics 30 and the bar 40 being at a fixed angle to the container. The eccentrics and base plate 40 are at a higher elevation at the entrance end than the exit end. Thus, the longitudinal component of vibratiton moves the mass of articles and media towards the exit end. However, legs 42 may be made adjustable to permit changes in the angle of inclination of the construction and thereby permit faster or slower travel of the articles and media from one end of the container to the other.

Adjacent the exit end of the container 12, there is provided a dam 44 against which the articles and media will bear as they reach the end of the container. The dam is adjustable in a vertical direction depending upon the level of articles and media desired to be maintained in the container. The dam includes a lower portion defined by the top edge 46, and the articles and media spill over this edge onto the discharge chute 18. In order to insure movement of the articles and media above the level of the edge 46, a deflector cylinder 48 is positioned adjacent the dam. As best shown in FIG. 3, this deflector cylinder causes the articles and media to rise upwardly beyond their normal level. In this connection, the articles and media are moving in a counterclockwise direction insofar as FIG. 3 is concerned.

The deflector cylinder 48 is secured to an adjusting 52 to the plate 54. By loosening the nut 56, the vertical rod 50 which is in turn attached by means of bracket position of the deflector cylinder can be adjusted and the deflector cylinder can be adjusted to a different angle with respect to the dam. These adjustments can be carried out to insure that the articles and media are discharged at a proper rate over the edge 46 of the dam 44, that the articles do not become jammed or become caught behind the edge 46, and that the articles do not recycle behind the dam instead of flowing over edge 46. In some cases, depending upon the size and type of articles being processed and the size and type of media being used, better operation can be achieved by removing the cylindrical deflector 48. FIG. 10 serves to schematically illustrate the disruption of the media level which occurs through the use of the cylindrical deflector.

Driving movement of the eccentrics is achieved by means of drive motor 62. The drive shaft 64 of this motor is connected by means of flexible couplings 68 and 70 to drive pulleys 72. The belts 74 and 76 operate to drive the eccentric shafts located on either side of the container 12.

FIG. 4 illustrates schematically the inferior vibrational motion within the container 78 of the construction and FIG. illustrates schematically the inferior vibrational motion Within the container 85 of the conventional vibrators having a single eccentric shaft below the container. In both instances, the view is looking toward the entry end of the constructions. Also in both instances the sizes of the circles and ellipses are exaggerated for sake of clarity but are in relative proportion to the type of vibration and amplitude.of vibration at each point inside the containers.

For maximum efiiciency the vibrational motion at all points within the container should be orbital, should be of the same magnitude of amplitude and should be of the same clockwise movement. As illustrated in FIG. 4, this is achieved by this invention since, in this instance, each of the eccentrics is rotating in a counter-clockwise direction and has an orbital amplitude represented by circles 80. The circles 77 within the container show that at every point the vibrational motion is orbital and is of the same magnitudes as the ecentrics. These motions also are counterclockwise. In addition to the vibrational movement represented by the circles, there is a slow roll of the mass of articles and media around the container in a clockwise direction. The surface of the mass of articles and media is somewhat higher on the left hand side as shown at 79.

The inferior vibrational motion of conventional vibrators is illustrated in FIG. 5. In this instance, the single eccentric has an orbital vibrational movement represented by the circle 82. At the extreme bottom of container 85, the motion as shown at 84 is slightly less orbital and more elliptical. At points along the vertical center line, the vibrational movement becomes progressively more elliptical from bottom to top or as the distance increases from the eccentric. Near the top the horizontal component of vibration is only a small percentage of that at the bottom as shown at 86 in FIG. 5. Also as shown, the vibrational movements at different points of the container are elliptical and are non-uniform.

From the bottom of container 85 up to the center of gravity 83 of the container and the mass of articles and media, all of the elliptical type vibrations are in a counterclockwise direction. Again, there is a slow roll of the mass of articles and media about the container 85 in a clockwise direction as shown by the large solid arrow in FIG. 5. Because of the inversion of the vibrational motion from counter-clockwise in the bottom half of the container to clockwise above the center of gravity, there is a force represented by the large dash line arrow trying to impede the slow roll of the articles and media in a clockwise direction. This slows down the roll of the articles and parts and creates a turbulent area shown at 81.

The fact that the construction illustrated in FIG. 4 provides a uniform counter-clockwise vibrational movement and a uniform roll of articles and media around the container greatly improves the efiiciency of the operation. In either a continuous type or a batch type operation of the type construction shown in FIG. 4, the total vibrating time can be substantially less while achieving equivalent finishing results. In comparing the same equipment having a single eccentric with equipment having a double eccentric attached in accordance with this invention, a removal rate approximately seven times as fast could be achieved with the new design. Furthermore, the horsepower required to move a given load was greatly reduced. This provides an added advantage since heavier loads could be employed and, therefore, materials such as relatively large steel balls can be used as media with this equipment.

FIGS. 7, 8 and 9 illustrate schematically the media level along the length of the container which typifies prior art constructions and constructions of the type contemplated by this invention. FIG. 7 illustrates the media level which usually occurs in a batch-type operation employing a single eccentric located beneath the bowl. The media level is lower at the two ends than at the center. This is due to the opposing force shown by the dash line arrow of FIG. 5, which tends to slow down the roll of the media, having a greater effect on the media where the ends of the container contacts the media. The roll of the media is slightly faster at the center than at the ends. In the con ventional continuous type vibrator constructions having a bottom eccentric, the media level is in nodes shown in FIG. 8.

With the construction of this invention, however, a much more level condition of the media will result, as shown in FIG. 9, for either continuous type or batch type machines. The media also rolls about the container at the same rate from end to end. Thus, a more positive and uniform roll of the media and a roll at a faster rpm. is achieved than with conventional vibrator constructions, which is beneficial in finishing operations.

In a specific test of the equipment, a 30 horsepower motor was used with a continuous type machine having the double eccentric construction and a 24-inch diameter bowl. The motor was operated at 1250 rpm. and only about horsepower was required to achieve the finishing operation. A load weighing 5000 pounds including steel balls as the media and metal articles were burnished in this test. The same load in a bowl of the same size but having a single bottom eccentric could not achieve rotation and roll with a horsepower motor because of the low eificiency of the conventional type. By greatly increasing the horsepower it might be possible to obtain roll of the media but because of machine stresses and bearing problems it would be impractical.

The constructions described are characterized by a variety of improved features. In the case of the continuous apparatus 10, the location of the inlets for media and articles has been found to be highly advantageous. Specifically, the media is introduced at a point ahead of the articles thereby eliminating a dead spot in the construction. Thus, articles entering through the inlet 16 will always encounter media previously introduced at 14 whereby there will be no hesitation before the mixture of articles and media begins movement in a spiral path.

Since there is no turbulent area as shown at 81 in FIG. 5 and since the level of the media is level as shown in FIG. 9 and since the roll of the media is faster than with conventional constructions, more uniform finishing and less damage to articles are achieved. In the conventional batch type, for example, articles being treated hesitate at the top of the roll and do not go back down uniformly with the media into the turbulent area. Also, the articles tend to separate from the media at the top of the roll and move toward and concentrate at the ends of the container. These tendencies often cause the articles to hit each other and damage them, which tendencies are avoided in this invention.

There is an opening 90 at the top of container 12 near the exit end which is covered by a removable plate 91. This is used, if necessary, as an observation port in the non-pressure continuous type of construction.

As indicated, the articles and media may be caused to flow onto discharge chute 18. It is contemplated, however, that the principles of the invention be associated with a construction of the pressure continuous type, for example, as described in copending application Ser. No. 725,756. For example, discharge chute 18 could be closed and plate 91 could be removed. The articles and media could then pass out through opening 90, thence over suitable handling equipment and screens for separation of the articles and media and for return of the media to entrance 14.

The use of twin eccentrics in the manner described provides the improved results when the eccentrics are located in accordance with the invention. Thus, the eccentric axes are located in a plane substantially corresponding with the center of gravity of the container 12 when it is loaded with articles and media. In view of the fact that the center of gravity will not be constant, the location of the eccentric axes must be approximated. Nevertheless, substantially improved results are achieved when the desired relationship is realized as closely as possible.

Although reference has been made to the use of twin eccentrics, it will be appreciated that the construction illustrated actually comprises four separate eccentrics coupled together in pairs. This provides an improved relationship since the load is spread over eight bearings. Where particularly heavy loads are handled, for example, when burnishing with steel balls, the load per bearing is substantially reduced so that an exceptional burden is not placed on the machine even though a heavy load is being treated.

It will be appreciated that the description covering movement of the articles and media relative to batch type equipment will be essentially the same in the case of continuous equipment with the exception of a longitudinal component of vibration which moves the mass toward the exit end. As indicated, the continuous construction may be mounted on an adjustable base so that the inclination from entry end to exit end can be varied, depending upon the particular application.

The construction of this invention provides many advantages in that faster finishing of articles can be achieved with less horsepower being required, with less damage to articles being finished and with less load on bearings and other components whereby maintenance costs can be substantially reduced. It is also emphasized that the ability to handle much heavier loads and to utilize much larger containers is extremely important. Larger and heavier media can be efficiently employed and much larger articles can be treated.

It will be understood that various changes and modifications may be made in the above described construction which provide the characteristics of this invention without departing from the spirit thereof, particularly as defined in the following claims.

That which is claimed is:

.1. In a vibrator construction wherein articles and media are disposed in a container which is associated with a movable supporting structure, and wherein vibrations are imparted to the container to achieve intimate contact between the articles and media, the improvement wherein the means for vibrating said containers comprise a pair of eccentric shafts, said shafts being laterally offset with respect to the axis of said container with one shaft being secured to said supporting structure on each side of the container, and wherein said eccentric shafts are positioned to lie approximately in the same plane as the center of gravity of the container when loaded with said articles and media.

2. A construction in accordance with claim 1 wherein said supporting structure is resiliently mounted.

3. A construction in accordance with claim 1 including a drive motor having drive means connecting said motor to the respective eccentric shafts.

4. A construction in accordance with claim 1 wherein said eccentric shafts carry at least two eccentrics on each side of the container, and including a set of bearing means for each eccentric.

5. A construction in accordance with claim 1 wherein said construction is of the batch type wherein said articles and media are inserted prior to vibration and are removed together at the completion of vibration.

6. A construction in accordance with claim 1 wherein said container includes an inlet for articles and media at one end and an outlet for articles and media at the other end whereby the articles and media can be moved continuously through the construction.

7. A construction in accordance with claim 6 wherein said eccentric shafts are set at a slight fixed angle of inclination to the longitudinal axis of said container and including a base which is adjustable in a vertical direction.

8. A construction in accordance with claim 6 including a darn located adjacent the outlet of said container, said darn including a higher portion serving as a barrier to the passage of articles and media toward said outlet,

7 and a lower portion over which said articles and media pass toward said outlet.

9. A construction in accordance with claim 8 including a deflector means extending longitudinally away from said dam on the side of said dam opposite said outlet, said deflector being located at approximately the junction of the higher and lower portions of the dam and operating to deflect articles and media upwardly for passage over the lower portion of the darn.

10. A construction in accordance with claim 6 wherein said inlet includes a first opening immediately adjacent the front end of the container for the introduction of finishing media, and a second opening immediately References Cited UNITED STATES PATENTS 7/1944 OConnor 5l163X 5/1961 Gould 5l-l63 10 TRAVIS S. MCGEHEE, Primary Examiner U.S. Cl. X.R. 24ll75; 25975 

